Turbine



Nov. 1, 1932. s COCK ET AL 1,885,512 Y TURBINE I Filed Oct. 21, 1931INVENTORS BY THEIR ATTORNEYS I I Patented Nov. 1, 1932 UNITED STATESPATENT OFFICE STANLEY SMITH COOK AND ANDREW PHILIP BENNETT, OFNEWCASTLE-ON-TYNE, .AND

CHARLES ALGERNON PARSONS, DECEASED, LATE OF NEWCASTLE-ON-TYNE, ENG-LAND, BY KATHERINE PARSONS, OF KIRKWHELPINGTON, VINCENT THOMPSON, OFNEWCASTLE-ON-T'YNE, AND FREDERICK GORDON HAY BEDFORD, OF WYLAM-ON- TYNE,ENGLAND, EXECUTORS; SAID COOK D SAID BENNETT ASSIGNORS TO SAID EXECUTOBSApplication filed October 21, 1931, Serial No. 570,118, and in GreatBritain October 18, 1930.

The invention relates to turbine units having ahead and astern sectionswithin a common casing.

A main object of the invention is to improve the lay-out of such aturbine unit with a view to securing advantages of the kind set forthbelow.

\Vith such an object, the present invention consists in a turbine unitcomprising the combinations of elements hereinafter described andparticularly pointed out in the claims.

The accompanying diagrammatic drawing shows an elevation partly insection through an ahead and astern turbine according to one form of theinvention.

In carrying the invention into effect ac-. cording to the form shownapplied to a steam turbine unit, the high-pressure ahead turbine, A, isof the reaction type, steam being admitted at one end, 2, of the rotorand exhausted at the other end, 3.

The astern turbine, B,- of the impulse type is mounted on the samerotor, 4, as the ahead turbine and is disposed within the same casing,5, at the inlet end of the ahead turbine, the astern steam admissionbeing shown at 6, and the exhaust at 7, adjacent the inlet end, 2, ofsaid vahead turbine. A conical diaphragm, 8, preferably integral withthe easing, 5, is provided with packing, 9, in relation to the rotorshaft, 4a, interposed between the ahead and astern turbines, A and B,and between this diaphragm, 8, and the highpressure blades, 10, a secondseal or packing is provided taking the form of a hollow cylinder, 11,having an internally-projecting flange, 12, bolted to the rotor, 4, androtatable within a corresponding cylinder, 13, with anexternally-projecting flange, 14, bolted to 0 a cylindrical wall, 15,projecting from the diaphragm, 8, and preferably integral therewith.

An annular leak-off space, C, more or less triangular in cross sectionis thus formed between the cylinder, 13, and the conical diaphragm, 8,and on the inner side .of the lat ter, this space being connected to thecondenser, F, by the outlet, 16, and pipe, 16a,

while a corresponding space, G, on the outside of the diaphragm receivesthe exhaust from the astern turbine, B. I

In order to minimize leakage from the ahead turbine to the space, C,-andso to the condenser and consequent loss of power, steam may betapped-off through the duct, 17 from an intermediate point of the lengthof the said second packing and led to chamber, D, formed by the addedwall, 18, and wall, 15, and thence by way of the outlet, 19, and pipe,19a, to the exhaust end of the ahead turbine, A.

It will be understood that the rotor, 4, is supported in the usualmanner in suitable bearmgs, E, E, outside the casing, through the endswalls of which it passes fluid-tight by help of suitable gland packing,20.

If desired, reaction blading may be used for the astern turbine also.

By virtue of the present invention the following advantages are obtainedWhen going ahead or astern, owing to the fact that the non-operativeturbine in accord-- ance with usual practice runs in a vacuum, there isno leakage of steam into the idle turbine, since the pressure on bothsides of the diaphragm gland, 9, when going ahead and of the secondpacking, 11, when going astern is the same, namely the pressure of thecondenser. Any steam leaking into the space, C, between the secondpacking, 11, and the diaphragm, 8, when going ahead and across thediaphragm gland, 9, when going astern passes direct to the condenser.Frictional losses and excessive heating and damage to the idle turbineare thus avoided.

In addition, the astern turbine, B, arranged at the hotter end, i. e.,the inlet end, of the high-pressure ahead turbine, A, is maintained at afairly high temperature by conducted heat, with the result that whensteam is admitted to the astern turbine, the latter is not so liable tosuffer from unequal expansions as in the ordinary construction.

Further, the large-diameter exhaust pipes connected to branches, 3 and7, are at opposite ends of the'unit and are thus more easily arrangedand connected to succeeding turbines, if any. Crowding and difficultpipe work are in this way avoided.

Finally, it will be seen that with the ahead ing and by a wallprojecting inwardly from turbine, A, in operation andthe astern tursaidcasing.

bine, B, running in a vacuum, the exhaust In testimony whereof we havesigned our pressure acting on the. left-hand end of the names to thisspecification.

ahead turbine is in excess of the condenser pressure in the space, C, sothat there is an. excess of pressure to the right balancing thePIFSSIIIG of the steam on the blades to the le t.

When, however, the ahead turbine, B, is in operation and the asternturbine, A, runs in a vacuum, there is no unbalanced pressure axially oneither the ahead or astern turbines.

In both cases, therefore, the ahead and astern turbines considered as asingle rotating unit are balanced in the longitudinal direction.

Departures may be made from the precise constructional forms describedwithout exceeding the scope of the invention.

Having now described the invention what is claimed as new and desired tosecure by Letters Patent is 1. An elastic-fluid parallel-flow turbineunit comprising an ahead turbine and an astern turbine having a commonrotor body and a common casin g, at least one of said turbines bein ofthe reaction type, the exhaust end of sai astern turbine being arrangedadjacent the inlet end of said ahead turbine,

easing diaphragm means between said ahead. and said astern turbines,said dia hragm means having walls spaced apart axially of said turbineswith a chamber therebetween, each wall being in substantiallyfluid-tight relation to said common rotor body, a condenser and meansfor connecting said chamber to said condenser.

2. An elastic-fluid parallelsflow turbine unit, com rising an aheadturbine and an astern tur ine having a common rotor body and a commoncasing, at least one of said turbines bein of the reaction type, theexhaust end of sai astern turbine being arranged adjacent the inlet endof said ahead turbine, casing diaphragm means between said ahead andsaid astern turbines, said diaphragm means'having walls spaced apartaxially of said turbines with a chamber therebetween, each wall being insubstantially fluid-tight relation to said common rotor body, acondenser and means for connecting said chamber to said condenser, anannular duct within said casing and surrounding said chamber, aconnection between said annular duct and a lower-pressure point of saidahead turbine and means for leading leakage to said an nular duct froman intermediate point of the fluid-tight path between said common rotorbody and that wall of said diaphragm means adjacent said ahead turbine.

An elastic-fluid turbine unit as claimed in claim 2, in which saidannular duct is bounded by said dia hragm means, by a wall projectingfrom sai diaphragm, by said cas- STANLEY SMITH COOK, ANDREW PHILPBENNETT, KATHERINE PARSONS. VINCENT THOMPSON, v FREDERICK GORDON HAYBEDFORD, Emccutors of Charles Algernon Parsons, Deceased.

